1. A spacecraft that is initially at rest turns on its engine at t = 0. If its mass is m = 3000 kg and the force from the engine is 45 N, what is the acceleration of the spacecraft?
2. A hockey puck moves on an icy surface that is frictionless, with a constant speed of 30 m/s. How long does it take the puck to travel the length of the hockey rink (60 m)?
3. An ice skater moves without friction on a frozen pond. While traveling at 8.0 m/s, she finds that it takes 17 s to travel the length of the pond. How long is the pond?
4. An object moves with a constant acceleration of 4.0 m/s2. If it starts with an initial speed of 30 m/s, how long does it take to reach a velocity of 250 m/s?